Galactomannan and polymerase chain reaction for the diagnosis of primary digestive aspergillosis in a patient with acute myeloid leukaemia

Intestinal Aspergillosis: Systematic Review on Patterns of Clinical Presentation and Management

Background: Intestinal aspergillosis (IA) is a rare entity primarily discovered in immunocompromised patients. Because of its low incidence, IA is not considered routinely in the differential of abdominal pain, distension, and diarrhea. A systematic characterization of demographics, comorbidities, clinical presentations, and outcomes can help surgeons recognize and manage IA in critically ill patients. Methods: Two independent authors carried out the literature search using PubMed, MEDLINE, and Scopus databases. The Mesh terms utilized were: 'intestinal' and 'aspergillosis' combined with the Boolean operator 'AND' (synonyms were combined with the Boolean operator 'OR'). Intestinal aspergillosis was defined as inflammation of the gastrointestinal tract (duodenum to rectum) caused by Aspergillus spp. All articles reporting IA were included. Articles describing aspergillosis of the esophagus or stomach were excluded. Statistical analysis was performed using SPSS software (version 18; SPSS Inc., Chicago, IL). Results: Forty-two articles reporting 56 cases were included in the study. Mean age was 44.9 ± 20.5 years. Male to female ratio was 29:27. The most common condition in patients who developed IA was transplantation (19 patients; 34%). The most common clinical presentations of IA were abdominal pain (21 patients; 38%) and diarrhea 12 patients; 21%). Sixty-six percent of patients had primary IA whereas 34% developed IA secondarily to systemic infection. Diagnostic modalities included exploratory laparotomy (35 patients; 63%) and endoscopy (7 patients; 13%). Mean time to diagnosis was 8.6 ± 11.3 days. Intestinal aspergillosis was limited to the small bowel in 61% of patients. In 43 (77%) patients, bowel resection is the definitive treatment, whereas 13 (23%) patients underwent antifungal therapy alone. Mortality rate was 39%. Sixty-three percent of patients treated with surgery survived, compared with 46% treated with antifungal therapy alone (p = 0.34). Conclusion: Intestinal aspergillosis is a life-threatening condition with a mortality rate of 39%. Extrapulmonary IA is seen in patients with neutropenia, sepsis, inflammatory conditions, and immunosuppression. Patients who undergo surgery are more likely to survive this infection.

Primary intestinal aspergillosis resulting in acute intestinal volvulus after autologous stem cell transplantation in a patient with relapsed non-Hodgkin lymphoma: report on a rare infectious complication and a review of the literature

Objectives: Since primary intestinal aspergillosis is a severe infectious complication with a high morbidity and mortality in immunocompromised patients, we want to draw attention to this rare entity and the importance of early recognition. Methods: We report a case of documented primary intestinal aspergillosis in a patient receiving an autologous stem cell transplantation (SCT). Furthermore, this article gives a short reflection on the occurrence of invasive aspergillosis in autologous SCT and the value of serum galactomannan levels based on literature search and linked with the case. Results: In this case the patient presented on day +8 after autologous SCT for a relapsed diffuse large B-cell lymphoma with an acute abdomen with urgent need for surgical intervention. Biopsy revealed the presence of fungal colonies due to aspergillosis and voriconazole was started. Until that day the systematically taken serum galactomannan tests were all negative or pending. Initially there was some resistance to perform surgery in the presence of neutropenia and thrombocytopenia but in the end it provided the definitive diagnosis and should not be delayed. Until now this patient is in good health and retains a complete remission. Conclusion: With this case, we would like to emphasize that early recognition of primary intestinal aspergillosis is of the utmost importance as it is a rare but serious infectious complication. It should be included in the differential diagnosis of neutropenic patients with sudden onset abdominal pain and ongoing fever, even in the absence of a positive serum galactomannan.

A retrospective series of gut aspergillosis in haematology patients

Gut invasive aspergillosis is an extremely rare infection in immunocompromised patients. The goal of this retrospective multicentre study is to report on cases of gut aspergillosis in haematology patients, including clinical presentation, risk factors, and outcome. Twenty-one patients from nine centres were identified. Eight had isolated gut aspergillosis, with no evidence of other infected sites, and 13 had disseminated aspergillosis. Thirteen patients had acute leukaemia. Nine were allogeneic stem cell transplant recipients. Clinical symptoms and imaging were poorly specific. The galactomannan antigenaemia test result was positive in 16/25 (64%) patients, including in four of the eight cases of isolated gut aspergillosis. Five of 21 patients had a dietary regimen rich in spices, suggesting that, in these cases, food could have been the source of gut colonization, and then of a primary gut Aspergillus lesion. The diagnosis was made post-mortem in six patients. The mortality rate in the remaining patients at 12 weeks was 7/15 (47%). Gut aspergillosis is probably misdiagnosed and underestimated in haematology patients, owing to the poor specificity of symptoms and imaging. Patients with a persistently positive galactomannan antigenaemia finding that is unexplained by respiratory lesions should be suspected of having gut aspergillosis in the presence of abdominal symptoms, and be quickly investigated. In the absence of severe abdominal complications leading to surgery and resection of the lesions, the optimal treatment is not yet defined.

Current Molecular Diagnostic Approaches to Systemic Infections withAspergillusSpecies in Patients with Hematological Malignancies

Within the recent years, novel molecular methods, especially PCR assays, have been developed to improve the diagnosis of invasive aspergillosis in patients with malignant hematological diseases being at high risk for this life-threatening infection. Early diagnosis and treatment are essential for adequate therapeutical management, which however, often remains difficult since most of the diagnostic tools used clinically at present either lack specificity or acceptable sensitivity. The clinical value, advantages and remaining problems of recently developed molecular approaches to detect the emerging fungal pathogen are reviewed.

Aspergillus flavus: an emerging non-fumigatus Aspergillus species of significance

Invasive aspergillosis is rare in immunocompetent people but contributes to significant morbidity and mortality in immunosuppressed patients. The majority (approximately 80%) of invasive Aspergillus infections is caused by Aspergillus fumigatus. The second most frequent (approximately 15-20%) pathogenic species is Aspergillus flavus and to a lesser extent, Aspergillus niger and Aspergillus terreus. Aspergillus flavus has emerged as a predominant pathogen in patients with fungal sinusitis and fungal keratitis in several institutions worldwide. To date, there has not been any publication exclusively reviewing the topic of A. flavus in the literature. This article reviews the microbiology, toxigenicity and epidemiology of A. flavus as well as describes the clinical characteristics, diagnosis and management of infections caused by this organism.

Internal amplification controls have not been employed in fungal PCR hence potential false negative results

Polymerase chain reaction (PCR) is subject to false negative results. Samples of fungi with the genes of interest (e.g. a disease or mycotoxin) may be categorized as negative and safe as a consequence. Fungi are eukaryotic organisms that are involved in many fields of human activity such as antibiotic, toxin and food production. Certain taxa are implicated in human, animal and plant diseases. However, fungi are difficult to identify and PCR techniques have been proposed increasingly for this purpose. Internal amplification controls (IACs) will ameliorate the situation and need to become mandatory. These are nucleic acids that posses a sequence which will provide a PCR product (i) using the same primers employed for the target gene, and (ii) that will not coincide on the gel with the product of the target gene. Only one group of workers employed an IAC, to respond to potential inhibition, which was reported in 1995 from this present assessment of numerous reports. Inhibitors in cultures need to be minimized, and secondary metabolites are an obvious source. The fields reviewed herein include medical mycology, mycotoxicology, environmental mycology and plant mycology. The conclusion is that previous reports are compromised because IACs have not been employed in fungal PCR; future research must include this control at an early stage.

Primary intestinal aspergillosis after high-dose chemotherapy and autologous stem cell rescue

Primary invasive aspergillosis of the gut is a rare event and is associated with high mortality. We report for the first time on a patient who had isolated aspergillosis of the small bowel after autologous stem cell transplantation. Diagnosis of invasive aspergillosis of the gut was based on abdominal pain, galactomannan antigenemia and isolation of Aspergillus fumigatus from the stool and was later confirmed by pathohistologic examination. No other site of invasive aspergillosis was evident. The patient was successfully treated with early surgery and combination antifungal therapy.

Clinical implications of environmental sources for Aspergillus

Invasive aspergillosis presents a formidable problem for both diagnosis and therapy. Therefore, prevention is a very important strategy in controlling this disease. Preventing invasive aspergillosis demands a clear understanding of the environmental sources of Aspergillus spp. and how this mould is transmitted to patients. Insight into the sources of exposure, mechanisms of transmission, and host susceptibility to infection are vital to appropriately direct preventive strategies to those settings where the risk of infection is the highest and consequently the impact of prevention the greatest.

Comparison of non-culture-based methods for detection of systemic fungal infections, with an emphasis on invasive Candida infections

The accepted limitations associated with classic culture techniques for the diagnosis of invasive fungal infections have lead to the emergence of many non-culture-based methods. With superior sensitivities and quicker turnaround times, non-culture-based methods may aid the diagnosis of invasive fungal infections. In this review of the diagnostic service, we assessed the performances of two antigen detection techniques (enzyme-linked immunosorbent assay [ELISA] and latex agglutination) with a molecular method for the detection of invasive Candida infection and invasive aspergillosis. The specificities for all three assays were high (> or = 97%), although the Candida PCR method had enhanced sensitivity over both ELISA and latex agglutination with values of 95%, 75%, and 25%, respectively. However, calculating significant sensitivity values for the Aspergillus detection methods was not feasible due to a low number of proven/probable cases. Despite enhanced sensitivity, the PCR method failed to detect nucleic acid in a probable case of invasive Candida infection that was detected by ELISA. In conclusion, both PCR and ELISA techniques should be used in unison to aid the detection of invasive fungal infections.

Aspergilluspolymerase chain reaction (PCR) diagnosis

In recent years novel molecular methods, notably polymerase chain reaction (PCR) assays, have been developed to improve the diagnosis of life-threatening invasive aspergillosis in patients at high risk, especially patients with malignant hematological disease. Early diagnosis and treatment are essential for adequate therapeutic management. Management, however, often remains difficult since most of the diagnostic tools used clinically at present either lack specificity or acceptable sensitivity. The clinical value, advantages and remaining problems of PCR approaches to detect the emerging fungal pathogen are reviewed.

Polymerase chain reaction in the diagnosis of invasive aspergillosis

In the present study, we present a patient with invasive pulmonary aspergillosis caused by Aspergillus fumigatus diagnosed by polymerase chain reaction (PCR) technique on blood and bronchoalveolar lavage fluid samples of the patient. The value of PCR in the diagnosis of aspergillosis is discussed.